1. Field of the Invention
The present invention relates generally to an orbital implant and, more particularly, to an integrated rigid fixation orbital expander to reduce deformation of the eye socket attributed to anophthalmos or microphthalmos.
2. Description of Related Art
The management of congenital anophthalmos or microphthalmos and early-acquired anophthalmos can be a challenge. Microphthalmos is a congenital or developmental anomaly in which the eyeballs are abnormally small, and occurs with a frequency of 0.22/1000 live births. Anophthalmos is a congenital defect in which an eye never developed in the socket. Both of these abnormalities present minified eyelids with abbreviated palpebral and bulbar conjunctivae. More critically, these two conditions are associated with ipsilateral hypoplasia of the bony orbit.
It is well recognized that orbital volume growth parallels ocular growth, and that the absence of an eye or reduced size of an eye will result in noticeable hemifacial deformity. Recent studies have demonstrated the efficacy of expandable orbital implants to stimulate bone growth and socket enlargement in the anophthalmic orbit. Pressure was found to be an effective stimulant for enlargement of the craniofacial skeleton.
However, insertion of currently available orbital tissue expanders is quite time-consuming and technically difficult in an infant. Furthermore, controlling the direction of expansion and maintaining rigid fixation of the implant in the orbit for uniformed expansion remain problematic. Frequently, the expander protrudes forward or even extrudes during the inflation process, displacing the conformer or breaking open the conjunctiva.
Accordingly, there is a need to address this problem.
Therefore, one aspect of the present invention is to provide an integrated rigid fixation orbital expander that can overcome the problems of the prior art.
It is another aspect of the invention to provide improved elements and arrangements of an integrated rigid fixation orbital expander for the purposes described which is inexpensive, dependable, and fully effective in accomplishing its intended purposes.
The integrated rigid fixation orbital expander according to one aspect of the invention includes a coupling tunnel, an injection port, and a substantially spherically shaped expansion chamber. The coupling tunnel is configured with opposing side walls, a top wall and a bottom wall. The opposing side walls are dimensioned with desired predetermined heights and the top and bottom walls are dimensioned with desired predetermined widths to conform with the thickness and width, respectively, of a plate that is used to prevent the expander from protruding forward, or out of socket during the inflation process, thus permitting controlled and uniformed expansion. Such a plate may be a plate having a vertical arm and a horizontal arm and a plurality of holes passing therethrough. The coupling tunnel accommodates the vertical arm of such a plate and holds the expander in a centrally located position during the inflation process. The horizontal arm or crossbar of the plate is fixed to the bony rim with screws. The plate may be a rigid and light material, e.g., titanium or the like.
The top wall of the coupling tunnel may have a depression denoting a mid-point of the coupling tunnel and serves as an entry point to introduce a needle for injection. The depression lines up with a hole on the vertical arm of the plate. The plate may glide within the coupling tunnel to align the depression with a desired hole in the plate. This alignment ensures that an injection needle is pointed perpendicular to the integrated rigid fixation orbital expander to gain entrance into the injection port.
The injection port may be housed within the expansion chamber. The injection port has a floor and a dome and a plurality of channels. The floor of the injection port may have a backstop plate to block a needle from further penetration, thereby avoiding inadvertent perforation of the integrated rigid fixation orbital expander. Once an insertion needle hits the backstop plate, injection of saline solution to inflate the integrated rigid fixation orbital expander may commence. The saline solution exits the injection port through the plurality of channels to fill the expander chamber. (The dome of the injection port is connected to the bottom wall of the coupling tunnel.)
The expansion chamber has a pre-inflation state and a post-inflation state corresponding to desired predetermined pre-inflation and post-inflation diameters, respectfully. The expansion chamber accommodates a volume of fluid required to inflate the expander to desired post-inflation state. Once the predetermined post-inflation state of the expander is reached, the expander remains in position until osseous growth equalizes the volume of the uninvolved orbit.
These and other aspects of the present invention will be described in or readily apparent upon further review of the following specification and drawings.